|
E.164 is an ITU-T recommendation, titled ''The international public telecommunication numbering plan'', that defines a numbering plan for the world-wide public switched telephone network (PSTN) and some other data networks. E.164 defines a general format for international telephone numbers. Plan-conforming numbers are limited to a maximum of 15 digits. The presentation of numbers is usually prefixed with the character ''+'' (plus sign), indicating that the number includes the international country calling code (country code), and must typically be prefixed when dialing with the appropriate international call prefix, which is a trunk code to reach an international circuit from within the country of call origination. The title of the original version and first revision of the E.164 standard was "Numbering Plan for the ISDN Era". ==Telephone number categories== This recommendation provides the number structure and functionality for the three categories of telephone numbers used for international public telecommunication: For each of the categories, it details the components of the numbering structure and the digit analysis required to successfully route the calls. Annex A provides additional information on the structure and function of E.164 numbers. Annex B provides information on network identification, service parameters, calling/connected line identity, dialing procedures, and addressing for Geographic-based ISDN calls. Specific E.164-based applications which differ in usage are defined in separate recommendations. The number categories are all based on a fifteen-digit numbering space. Before 1997, only twelve digits were allowed. The definition does not include any trunk dialing codes, necessary for a call to reach international circuits from inside the country of call origination. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「E.164」の詳細全文を読む スポンサード リンク
|